1 /* 2 * This program is free software; you can redistribute it and/or modify 3 * it under the terms of the GNU General Public License as published by 4 * the Free Software Foundation; either version 2 of the License, or 5 * (at your option) any later version. 6 * 7 * Copyright (C) Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk) 8 */ 9 #include <linux/errno.h> 10 #include <linux/types.h> 11 #include <linux/socket.h> 12 #include <linux/in.h> 13 #include <linux/kernel.h> 14 #include <linux/module.h> 15 #include <linux/spinlock.h> 16 #include <linux/timer.h> 17 #include <linux/string.h> 18 #include <linux/sockios.h> 19 #include <linux/net.h> 20 #include <linux/slab.h> 21 #include <net/ax25.h> 22 #include <linux/inet.h> 23 #include <linux/netdevice.h> 24 #include <linux/skbuff.h> 25 #include <net/sock.h> 26 #include <linux/uaccess.h> 27 #include <linux/fcntl.h> 28 #include <linux/mm.h> 29 #include <linux/interrupt.h> 30 31 static struct ax25_protocol *protocol_list; 32 static DEFINE_RWLOCK(protocol_list_lock); 33 34 static HLIST_HEAD(ax25_linkfail_list); 35 static DEFINE_SPINLOCK(linkfail_lock); 36 37 static struct listen_struct { 38 struct listen_struct *next; 39 ax25_address callsign; 40 struct net_device *dev; 41 } *listen_list = NULL; 42 static DEFINE_SPINLOCK(listen_lock); 43 44 /* 45 * Do not register the internal protocols AX25_P_TEXT, AX25_P_SEGMENT, 46 * AX25_P_IP or AX25_P_ARP ... 47 */ 48 void ax25_register_pid(struct ax25_protocol *ap) 49 { 50 write_lock_bh(&protocol_list_lock); 51 ap->next = protocol_list; 52 protocol_list = ap; 53 write_unlock_bh(&protocol_list_lock); 54 } 55 56 EXPORT_SYMBOL_GPL(ax25_register_pid); 57 58 void ax25_protocol_release(unsigned int pid) 59 { 60 struct ax25_protocol *protocol; 61 62 write_lock_bh(&protocol_list_lock); 63 protocol = protocol_list; 64 if (protocol == NULL) 65 goto out; 66 67 if (protocol->pid == pid) { 68 protocol_list = protocol->next; 69 goto out; 70 } 71 72 while (protocol != NULL && protocol->next != NULL) { 73 if (protocol->next->pid == pid) { 74 protocol->next = protocol->next->next; 75 goto out; 76 } 77 78 protocol = protocol->next; 79 } 80 out: 81 write_unlock_bh(&protocol_list_lock); 82 } 83 84 EXPORT_SYMBOL(ax25_protocol_release); 85 86 void ax25_linkfail_register(struct ax25_linkfail *lf) 87 { 88 spin_lock_bh(&linkfail_lock); 89 hlist_add_head(&lf->lf_node, &ax25_linkfail_list); 90 spin_unlock_bh(&linkfail_lock); 91 } 92 93 EXPORT_SYMBOL(ax25_linkfail_register); 94 95 void ax25_linkfail_release(struct ax25_linkfail *lf) 96 { 97 spin_lock_bh(&linkfail_lock); 98 hlist_del_init(&lf->lf_node); 99 spin_unlock_bh(&linkfail_lock); 100 } 101 102 EXPORT_SYMBOL(ax25_linkfail_release); 103 104 int ax25_listen_register(ax25_address *callsign, struct net_device *dev) 105 { 106 struct listen_struct *listen; 107 108 if (ax25_listen_mine(callsign, dev)) 109 return 0; 110 111 if ((listen = kmalloc(sizeof(*listen), GFP_ATOMIC)) == NULL) 112 return -ENOMEM; 113 114 listen->callsign = *callsign; 115 listen->dev = dev; 116 117 spin_lock_bh(&listen_lock); 118 listen->next = listen_list; 119 listen_list = listen; 120 spin_unlock_bh(&listen_lock); 121 122 return 0; 123 } 124 125 EXPORT_SYMBOL(ax25_listen_register); 126 127 void ax25_listen_release(ax25_address *callsign, struct net_device *dev) 128 { 129 struct listen_struct *s, *listen; 130 131 spin_lock_bh(&listen_lock); 132 listen = listen_list; 133 if (listen == NULL) { 134 spin_unlock_bh(&listen_lock); 135 return; 136 } 137 138 if (ax25cmp(&listen->callsign, callsign) == 0 && listen->dev == dev) { 139 listen_list = listen->next; 140 spin_unlock_bh(&listen_lock); 141 kfree(listen); 142 return; 143 } 144 145 while (listen != NULL && listen->next != NULL) { 146 if (ax25cmp(&listen->next->callsign, callsign) == 0 && listen->next->dev == dev) { 147 s = listen->next; 148 listen->next = listen->next->next; 149 spin_unlock_bh(&listen_lock); 150 kfree(s); 151 return; 152 } 153 154 listen = listen->next; 155 } 156 spin_unlock_bh(&listen_lock); 157 } 158 159 EXPORT_SYMBOL(ax25_listen_release); 160 161 int (*ax25_protocol_function(unsigned int pid))(struct sk_buff *, ax25_cb *) 162 { 163 int (*res)(struct sk_buff *, ax25_cb *) = NULL; 164 struct ax25_protocol *protocol; 165 166 read_lock(&protocol_list_lock); 167 for (protocol = protocol_list; protocol != NULL; protocol = protocol->next) 168 if (protocol->pid == pid) { 169 res = protocol->func; 170 break; 171 } 172 read_unlock(&protocol_list_lock); 173 174 return res; 175 } 176 177 int ax25_listen_mine(ax25_address *callsign, struct net_device *dev) 178 { 179 struct listen_struct *listen; 180 181 spin_lock_bh(&listen_lock); 182 for (listen = listen_list; listen != NULL; listen = listen->next) 183 if (ax25cmp(&listen->callsign, callsign) == 0 && 184 (listen->dev == dev || listen->dev == NULL)) { 185 spin_unlock_bh(&listen_lock); 186 return 1; 187 } 188 spin_unlock_bh(&listen_lock); 189 190 return 0; 191 } 192 193 void ax25_link_failed(ax25_cb *ax25, int reason) 194 { 195 struct ax25_linkfail *lf; 196 197 spin_lock_bh(&linkfail_lock); 198 hlist_for_each_entry(lf, &ax25_linkfail_list, lf_node) 199 lf->func(ax25, reason); 200 spin_unlock_bh(&linkfail_lock); 201 } 202 203 int ax25_protocol_is_registered(unsigned int pid) 204 { 205 struct ax25_protocol *protocol; 206 int res = 0; 207 208 read_lock_bh(&protocol_list_lock); 209 for (protocol = protocol_list; protocol != NULL; protocol = protocol->next) 210 if (protocol->pid == pid) { 211 res = 1; 212 break; 213 } 214 read_unlock_bh(&protocol_list_lock); 215 216 return res; 217 } 218